Rhodiola

SAD is a seasonal form of depression that often presents with low energy, hypersomnia/fatigue, and low mood in winter. Rhodiola is an adaptogen historically used to reduce fatigue and improve stress resilience and mood; those properties map onto the common symptoms of SAD (fatigue, low energy, low mood). OASK Publishers

Neurotransmitter / biochemical actions: Rhodiola extracts (especially standardized extracts such as SHR-5) have been shown in lab studies to influence central monoamines (serotonin, norepinephrine, dopamine), inhibit monoamine oxidase A/B in vitro, and modify β-endorphin/cortisol responses to stress. These effects provide plausible biological reasons Rhodiola can improve mood, energy and stress-related fatigue — mechanisms relevant to SAD. Accurate Clinic

Clinical signal in related conditions: Randomized trials show benefit for stress-related fatigue and for mild–moderate depressive episodes (the latter relevant because many SAD cases are mild–moderate depression). While trials usually studied “depression” or “stress-related fatigue” rather than SAD specifically, the symptomatic overlap (low energy, winter pattern) is why clinicians and guides sometimes recommend Rhodiola for winter depressive tendencies. Bottom line: biologically plausible and supported by small clinical trials for related conditions — but evidence specifically for SAD is limited compared with first-line treatments (light therapy, CBT, antidepressants). scicompdf.se

Forms/standardization

• Use a standardized extract (studies commonly use the SHR-5 extract or extracts standardized to rosavins and salidroside). Look for product labels showing rosavins ≈ 2–3% and salidroside (rhodioloside) content. Accurate Clinic

Doses used in clinical trials

• Common effective ranges in trials:
• 340 mg/day (SHR-5) and 680 mg/day have been used with positive results in a 6-week randomized trial. medref.se
• Another trial (proof-of-concept vs sertraline) used one 340 mg SHR-5 capsule as the starting unit and applied dose escalation up to 4 capsules/day (≈1,360 mg/day) if insufficient early response — the trial used escalation rules over 12 weeks. (That study overall found fewer side effects with Rhodiola but smaller antidepressant effect than sertraline.) Accurate Clinic
• Other fatigue studies used ~400–576 mg/day (divided doses) with benefit. scicompdf.se

Practical, trial-based guidance (how people typically use it)

• Start with a standardized extract 200–340 mg once daily in the morning (many clinicians recommend morning because Rhodiola can be stimulating). If tolerated but not effective by 2–4 weeks, some trial protocols escalated to ~340–680 mg/day (divided or once daily depending on the product). More aggressive escalation up to ~1,000–1,360 mg/day was used in a controlled trial under supervision; that was NOT necessary in most positive trials. Accurate Clinic
• Timing: take in the morning or early afternoon (avoid near bedtime because it can cause insomnia in some people). Experience Life
• Duration: clinical trials typically measure outcomes at 6 weeks (some at 12 weeks). Expect 6–12 weeks to assess benefit. If no improvement after an adequate trial, stop and discuss alternatives (light therapy, CBT, antidepressant) with your clinician. Europe PMC

Randomized clinical trials

• Darbinyan V. et al., Nord J Psychiatry 2007 — SHR-5 extract 340 mg/day and 680 mg/day vs placebo in mild–moderate depression (6 weeks) — reported antidepressant potency at those doses. (PDF of the trial.) medref.se
• Link: Clinical trial (Darbinyan 2007). medref.se
• Olsson EMG et al., Planta Medica 2009 — randomized, double-blind SHR-5 (≈576 mg/day) vs placebo for stress-related fatigue; showed significant improvement in fatigue/performance measures. scicompdf.se
• Mao JJ et al., Phytomedicine 2015 — Rhodiola vs sertraline vs placebo in mild–moderate major depressive disorder (12 weeks). Rhodiola produced clinically meaningful improvement with fewer adverse events than sertraline, though the antidepressant effect was smaller vs sertraline in this underpowered trial. This is the first randomized, placebo-controlled head-to-head comparison with sertraline. (Full trial PDF.) Accurate Clinic

Mechanism / pharmacology reviews

• Panossian & Wikman and more recent reviews summarize mechanisms (monoamines, MAO inhibition, stress hormone modulation, antioxidant/anti-inflammatory effects). See review articles and a recent molecular mechanisms review. ScienceDirect

Regulatory / evidence summaries

• NCCIH (U.S. National Center for Complementary and Integrative Health) — summarizes evidence, safety signals, and notes that while short-term studies (6–12 weeks) show possible benefit, overall evidence is limited and larger trials are needed. NCCIH

Summary: Multiple randomized trials (small to moderate size) support benefit for fatigue, stress-related fatigue, and mild–moderate depressive symptoms at ~340–680 mg/day; one head-to-head trial vs sertraline showed fewer side effects but smaller antidepressant effect. However, large definitive trials specifically in SAD are lacking; the evidence is suggestive rather than conclusive. Europe PMC